Why did concrete screws feel loose when installed in a brick wall

fastenermortar

I am trying to secure a floating mantle shelf over a brick fireplace wall.

I used 2 3/4" 3/16 tapcon screws to secure the strip of wood to a brick wall but the wood strip did not hold securely

The tapcon 3/16" screws called for a 5/32 mortar bit hole which I used, but when I drilled the tapcon screws into the mortar they felt loose, as if the hole was too big.

Any guesses as to what might have gone wrong? Any suggestions as what type of fasteners would work better in securing the wood strip to the brick wall?

Best Answer

Tapconing into a mortar joint is to be avoided.

See the discussion here.

And the one here about how 3/16" are garbage. Use 1/4".


If the Tapcon goes into a mortar joint it's pull out strength will depend on the compressive PSI of the mortar and the depth of the mortar joint in combination with the length & diameter of the Tapcon.

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